They were holed up in a flat in a multi-storey apartment block in the town of Khasavyurt, surrounded by police special forces.

As people were being evacuated from the apartment block, the gunmen refused to surrender and opened fire.

The special operation continued for more than four hours ending early on Monday morning, after the group had been eliminated.

“During the combat assault three people including a woman, who made up a stout resistance, were killed,” a source in FSB told Interfax.

The same source also said the gunmen’s identities had already been confirmed. One of them was local terrorist group leader, 30-year-old Arslan Egilbaev. The other two, both 27, were Egilbaev’s followers.

In the flat where the three people had been holding out, police found two automatic weapons, several grenades, lots of ammunition, and pious literature.